新疆阿尔金地区约马克其铜矿床特征

Features of Yuemakeqi Copper Deposit in Altyn Area, Xinjiang Autonomous Region

约马克其铜矿床由河南省地质调查院通过化探扫面、异常查证、资源评价发现.该矿床位于阿尔金成矿带中段,所处大地构造环境非常复杂.矿床受沿阿尔金南缘断裂带分布的约马克其基性-超基性杂岩体控制.杂岩体主要岩石类型为:辉长岩、辉长辉绿岩、辉石岩、橄榄辉石岩等.岩石蚀变强烈,常见有蛇纹石化、绿帘石化、绿泥石化、硅化、绢云母化等蚀变,普遍发育黄铁矿化、孔雀石化.铜矿床是由近平行展布的4个铜矿化带组成,矿化带似层状,赋存于辉长辉绿岩中,与围岩呈渐变过渡关系.矿体走向近东西,倾向南,倾角60°～85°.铜品位在0.20%～2.75%之间,伴有金、镍、铂、钯矿化,金多在0.10 × 10-6～0.50 × 10-6之间,镍多在0.10%～0.20%之间,铂和钯多在0.10 ×10-6～1.0 × 10-6之间.区域异常元素组合为Cu、Au、Cr、Ni、Go为主;微量元素富集Gu、Cr、Ni、Au、Ag、Pt、Pb;轻稀土富集.约马克其铜矿床是岩浆分异的产物,形成于大陆环境,区域上存有众多与之相似的成矿环境,找矿潜力巨大.

Yuemakeqi copper deposit is found by Henan Institute of Geological Survey through the geological exploration, anomaly investigation and resource evaluation. The deposit is located in the middle of the Altyn mineralization belt with very complicated tectonic setting. And it is controlled by the Yuemakeqi mafic-ultramafic complexes distributing along the fault belt in the southern margin of Altyn. The main rocks in the complex are gabbro, gabbro-diabase, pyroxenite and olivine-pyroxenite etc. The rocks alternate badly with serpentinization, epidotization, chloritization, silication, swrucitization, pyritization, malachitization etc. The copper deposit developed four mineralization belts distrabuting parallelly with the stratoid structure in the gabbro-diabase which change gradually to the country rocks. The ore strikes almost EW, dips southwardly, and the dip angle is 60° ～ 85°. The copper grade is 0.20% ～ 2.75%, and Au, Ni, Pt and Pd can be seen too. The Au grade is 0.10×10 -6 ～ 0.50×10 -6, Ni 0.10% ～ 0.20%, Pt and Pd 0.10×10 -6 ～ 1.0×10 -6. The regional anomaly constitution is Cu、Au、Cr、Ni、Co. The trace elements are rich in Cu、Cr、Ni、Au、Ag、Pt、Pb. The copper deposit is production of the magmatic differentiation and formed in the continental setting. There are many places similar to it, so the ore-search potential is very great.